Functional morphology of chloride cells in killifish Fundulus heteroclitus, a euryhaline teleost with seawater preference

ABSTRACT:   Recent advances in the functional morphology of chloride cells in killifish Fundulus heteroclitus , a euryhaline teleost with seawater (SW) preference, were reviewed. Immunocytochemical detection of chloride cells with anti-Na⁺/K⁺-ATPase revealed transitional processes of the chloride cell distribution during early life stages. Chloride cells first appear in the yolk-sac membrane at an early embryonic stage, followed by their appearance in the body skin in the later embryonic stages. The principal site for the chloride cell distribution then shifts from the yolk-sac membrane and body skin during embryonic stages to the gills and opercular membrane in larval and later developmental stages. Morphologically distinct SW- and freshwater (FW)-type chloride cells were identified in adult killifish adapted to SW and FW, respectively. Both types of chloride cells are equally active in the two environments, but exert different ion-transporting functions. Following direct transfer of killifish from SW to FW, SW-type chloride cells were transformed into FW-type cells as a short-term response, followed by the promotion of chloride cell replacement as a long-term response. In killifish acclimated to low NaCl (0.1 mM) FW, intense immunoreactivity for vacuolar-type proton pump (V-ATPase) was detected in the basolateral membrane of FW-type chloride cells, whereas the immunoreactivity was much weaker in fish acclimated to FW with higher NaCl concentrations (1.0 and 10.0 mM). These results suggest the occurrence of active ion absorption in FW-type chloride cells and the involvement of V-ATPase in ion-absorbing mechanisms. In view of recent advances in this field, future chloride cell research should be considered in relation to the functional diversity of chloride cells.     

Potential predictive biomarkers of obesity in Burmese cats

Australian Burmese cats are predisposed to diabetes mellitus and, compared to other breeds, have delayed triglyceride clearance that may result in subtle changes within cells and tissues that trigger specific alterations in gene expression within peripheral blood leucocytes (PBLs). Expression of genes involved in energy metabolism (glucose-6-phosphate dehydrogenase and malate dehydrogenase), lipogenesis (ATP citrate lyase [ACL], fatty acid synthase [FAS] and sterol regulatory binding protein-1c [SREBP-1c]), and insulin signalling (insulin receptor substrates 1 and 2, and phosphatidylinositol-3 kinase), as well as cholesterol lipoprotein subfraction profiling were carried out on PBLs from lean Burmese cats and compared with similar profiles of age and gender matched lean and obese Australian domestic shorthaired cats (DSHs) in an attempt to identify possible biomarkers for assessing obesity.For the majority of the genes examined, the lean Burmese cats demonstrated similar PBL gene expression patterns as age and gender matched obese Australian DSH cats. Lean Burmese had increased expression of ACL and FAS, but not SREBP-1c, a main upstream regulator of lipid synthesis, suggesting possible aberrations in lipogenesis. Moreover, lean Burmese displayed a 3- to 4-fold increase in the very low density cholesterol fraction percentage, which was double that for obese DSH cats, indicating an increased degree of lipid dysregulation especially in relation to triglycerides. The findings suggest that Burmese cats may have a particular propensity for dysregulation in lipid metabolism.     

Local convergence zones or discontinuous lines in the Taklimakan Desert, Northwest China

In order to study convergence zones or discontinuous lines formed locally in the Taklimakan Desert,we analyzed available MODIS images onboad TERRA or AQUA satellite for ten cases:29 March 2002,14 April 2002;2 January 2003;21 April 2003;26 March 2004;28 April 2004;30 January 2005;25 June 2005;3 December 2005;and 26 July 2006.We used weather maps published by the Japan Mete-orological Agency for the Asia and Pacific region at 500 hPa,700 hPa and 850 hPa,at 00Z and 12Z to analyze the meteorological conditions occurring in each case.We estimated the positions of air streams,convergence zones or discontinuous lines between them,and thermal conditions on the maps and con-firmed the presence of cumulus and cumulonimbus clouds through satellite images in particular.After a review of previous studies,this paper introduced the results of the present study.Closed warm areas in the Taklimakan Desert and on the Tibetan Plateau and local convergence zones or discontinuous lines in the Taklimakan Desert were discussed together with their diurnal changes,using composite maps of the ten cases.Along the long axis of the desert the convergence zones or discontinuous lines normally extend 70-80 km in a west-east direction,but are suspected to exceed 100 km in extreme cases.On the other hand,the convergence zones or discontinuous lines extending in a north-south direction on the southern fringe of the desert have a length of 40-60 km.The closed warm areas show clear diurnal changes,but they were not detected at the 500 hPa level.An example of a clear convergence zone running in a north-south direction on 26 July 2006 was presented in detail with corresponding satellite images.     

Trends in the prevalence of anaemia in Japanese adult women, 1989-2003

OBJECTIVE: There is an increasing concern of anaemia in Japanese women, but no national trend data has existed to date. We analysed long-term national trends of anaemia in adult women. DESIGN: Secondary analyses of 15 consecutive cross-sectional nationwide surveys conducted during the period 1989-2003. Analyses were based on 5-year intervals (1989-1993, 1994-1998, 1999-2003). SETTING: Japan. SUBJECTS: The subjects included the National Health and Nutrition Survey of Japan (NHNS-J) population. Analyses were based on 50 967 non-pregnant/non-lactating women aged 20 years and over, with complete data sets. We stratified subjects into six age groups (20-29 years, 30-39 years, 40-49 years, 50-59 years, 60-69 years and 70+ years), and three age groups (20-49 years, 50-69 years, 70+ years) for analyses on residential areas (metropolitan, cities and towns). RESULTS: Decreases in trends of mean haemoglobin values (intravenous) were significant in all age groups. Changes in the prevalence of anaemia were significant only in women aged 30-39 and 40-49 years. Anaemia (haemoglobin < 12.0 g dl-1) increased from 16.8% to 20.6% in women aged 30-39 years, and from 20.2% to 26.9% in women aged 40-49 years, respectively. Prevalence was highest in women aged 70 years and older in all times, but no significant change was observed. CONCLUSIONS: Haemoglobin values have declined significantly in all ages in the last 15 years. Anaemia was especially significant in women aged 30-39 years and 40-49 years. Our findings suggest that a large number of young women in Japan are at risk of anaemia, so continuous monitoring and controlling efforts of this trend are needed.     

Changes in peripheral lymphocyte subsets in the type 1 diabetic dogs treated with insulin injections

Plasma metabolites and peripheral lymphocyte subsets were measured in ten diabetic and ten control dogs to investigate their significances as indicators to evaluate immune states in the diabetic dogs. Diabetic dogs were treated with insulin injections, however their plasma glucose and fructosamine concentrations were significantly higher than those of the controls. There were no significant differences in counts of total white blood cells (WBC) and lymphocyte CD8(+) cells (cytotoxic T cells) between the control and the diabetic dogs. In the diabetic dogs, the counts of CD3(+) (T cells), CD4(+) (Helper T cells) and CD21(+) (B cells) cells and the peripheral lymphocytes CD4/CD8 ratio were significantly lower than those in the control dogs. We confirmed abnormality of lymphocyte subsets in insulin treated diabetic dogs and it may relate to depression of immunocompetence and high susceptibility to common infectious diseases.     

A rapid multiple immunofluorescence method for the simultaneous detection of CD20 and CD3 in canine and feline cytological samples

CD20 and CD3 are considered reliable markers for B and T cells, respectively. This study aimed to develop a rapid multiple immunofluorescence (RMIF) method for the detection of CD20 and CD3 on a single cytology slide. Air-dried smears were prepared using samples collected from dogs (n=26) and cats (n=6). Immunosignal detection using the newly developed method required 60 min. Clear immunosignals for CD20 and CD3 were detected in 24 of 26 samples in dogs and in all 6 cats. As the RMIF (CD20/CD3) method can detect markers of both B and T cells simultaneously on a single cytology smear, it would be an efficient tool for the immunophenotyping of canine and feline lymphoma samples.     

Derived muscle arrangements and their shared innervation patterns of external and internal cheek pouches in rodents

Cheek pouches have evolved from the oral cavity in rodents and act as temporary food storage repositories. There are two types of opening, internal and external. Details about the complex cutaneous muscles controlling the pouches have still not been fully elucidated. To understand the shared and derived traits of the muscles surrounding the cheek pouch and their innervation, we carried out an evolutionary morphological study using two desert kangaroo rats (Dipodomys deserti) and three plains pocket gophers (Geomys bursarius) from each of the two families equipped with external cheek pouches, and four Syrian hamsters (Mesocricetus auratus) with internal cheek pouches. The most conspicuous derived trait of the muscles between the external and internal cheek pouches, the sphincter sacculi, surrounds almost all of the edge of the outer entrance of the pouch. It is present in both species with external pouches, but not in hamsters, which have internal pouches. Our neurological findings demonstrate that most pouch muscles are innervated by both the facial and the cervical nerves, regardless of the pouch type. In these dually innervated muscles, the ventromedial part of the muscles tends to be innervated dominantly or uniquely by the cervical nerves, which usually enter from the superficial or lateral aspect. As a trait shared with the cervical nerves innervating the propatagial muscles in aerodynamic mammals such as bats and flying squirrels, and panniculus carnosus in most mammals, our neurological evidence suggests that the cervical nerve has the potential to innervate derived cutaneous muscles in the cervicofacial region.     

The origin of planetary impactors in the inner solar system

Insights into the history of the inner solar system can be derived from the impact cratering record of the Moon, Mars, Venus, and Mercury and from the size distributions of asteroid populations. Old craters from a unique period of heavy bombardment that ended approximately 3.8 billion years ago were made by asteroids that were dynamically ejected from the main asteroid belt, possibly due to the orbital migration of the giant planets. The impactors of the past approximately 3.8 billion years have a size distribution quite different from that of the main belt asteroids but very similar to that of near-Earth asteroids.     

Genetic and morphological evidence of hybridization between <Emphasis Type="Italic">Nematalosa japonica</Emphasis> and <Emphasis Type="Italic">N. come</Emphasis> (Clupeiformes: Clupeidae) off Okinawa Island,Ryukyu Archipelago,Japan

Two morphologically similar species of gizzard shad, Nematalosa japonica Regan and N. come (Richardson), sympatrically distributed off Okinawa Island, Japan, were examined using an allozyme locus (SOD*) and two nuclear polymerase chain reaction (PCR)-based DNA markers (ITS-1 and CaM), which provided diagnostic identification of each species. In addition, a multiplex PCR-based mitochondrial DNA (mtDNA) marker (16S) was used to characterize the distribution of mtDNA haplotypes among specimens. The species composition of sympatric and allopatric population samples from Tungkang, southern Taiwan, to Okinawa and the Shikoku Islands, Japan, were also examined. Gizzard shad with hybrid genotypes were detected in three populations from Okinawa Island, with hybrid frequency ranging from 1 to 67%. A backcross level of 2% was detected in the dominant hybrid frequencies of one population sample only. Morphological examination of hybrids showed intermediate forms, with hybrid indices of three meristic characters falling between those of the parental species (range 39–53; mean 45). Although principal component analysis showed differences between N. japonica and N. come based on the first principal component scores, hybrids were difficult to identify. Accordingly, satisfactory identification of species and hybrids could be achieved only using genetic tools. We also discuss the cause of hybridization and its relationship with recently conducted reclamation on Okinawa Island.     

A rhabdomyosarcoma arising in the larynx of a dog

A neoplastic nodular lesion, 2 × 3 cm in diameter, was found in the larynx of a 6-year-old spayed female dog. The tumor was ill-circumscribed, consisting histologically of large round cells with abundant cytoplasm interspersed with small round cells with less cytoplasm and occasional multinucleated cells (myotubes). Immunohistochemically, tumor cells were positive for myoglobin, desmin and vimentin in varying degrees, but negative for S-100 protein, GFAP or cytokeratin. Cytoplasmic myofilaments/myofibrils with a dense Z-line-like structure were seen, the fine structures of which were complemented by PTAH stain. Based on these findings, the tumor was diagnosed as a rhabdomyosarcoma, a very rare tumor in the larynx of dogs.